Solar Water Heating Quote, reasonable ?

[isie]

The bigger the geyser the more panels it has. my 200 has one panel and the 300 has two. I try not to use the electric as far as possible especially since i work shifts and so i do not shower at the same time of day always. On day shift i shower after work ie in the evening. On night shift i shower after work ie in the morning. I alternate day and night shift weekly. I have not found a controller smart enough to follow my shift pattern well enough to switch on just before i am due for a shower and i am to lazy to build and program one although i am pretty sure that i could. What i can say is this. my two geysers came from different competing companies. Both told me that you needed a bigger one. I took their advice in both cases and there is no doubt (after 13 years) that hot water availability is about the same as the original smaller electric ones.

pretty much most decent controllers will "switch" on based on the time set - but will only use electricity if the water temperature is not at or close to the required temp.

probably 6 and 1/2 a dozen argument but I just think in terms of electric heating the larger one is a waste if you don't need that volume of water.

 

[charlieharper]

I've got an existing Kwiksol 200 geyser (installed late 2018) and got a R25k quote to convert it to solar + 1 extra 2.5 SqM solar plate.... excessive?

 

[Bonywasawarrioraway]

pretty much most decent controllers will "switch" on based on the time set - but will only use electricity if the water temperature is not at or close to the required temp.

probably 6 and 1/2 a dozen argument but I just think in terms of electric heating the larger one is a waste if you don't need that volume of water.

I hear what you are saying. I should have been more clear. the theory is this: in a pressure geyser as you use hot water, it is replaced in the geyser by cold water. In an electric geyser this immediately kicks in the element to return the whole volume to the preset temperature.
In a solar geyser the re-heat only occurs during the set time (on your fancy timer - this is the only time the element can engage.) or during the day when the sun shines again. Put simply it re-heats slower.

So, its is not about the volume of water as much as it is about the temperature of that water.

The amount one shower cools the water in the geyser by is determined by the ratio between how much water was used and the capacity of the geyser. So for the average shower the temp of the water in a small geyser will be reduced more than that in a large geyser. Ergo for this type of geyser bigger is better.

While they definitely save you money in the long run, make no mistake they are expensive. Buy one that is too small in order to save a few grand and you will suffer serious buyer's remorse and perhaps even be tempted to hold the view that they do not work and are a waste of time and money.

Most controllers are perfect for most people. Its just me with my disastrous working hours and therefore variable ablution times where they fall flat, and even then, only in winter. Ignore the controller comments, just me venting. The big issue you need to understand if you are not to be disappointed is the volume one.

Solar geysers are heated less frequently than electric so if you want to have enough hot water, you need a bigger one.

i hope that clears it up.

 

[chrisc]

1 x 2.5 sqm collector panel is too small
I had 2, 2.5 sqm panels, these were just enough. Superb in summer, hopeless in (Cape Town) winter
When these failed due to corrosion, I got a 20 tube evacuated tube collector. Twice as efficient and more working days than non-working days
In winter, 2 hours of moderate sun heats the water to 60 deg

 

[Bonywasawarrioraway]

Thanks, guys. It confirms my suspicions.
I will probably just get them to replace the geyser only. As I understand I can retrofit the solar portion later.

Or, seeing as I already have an Inverter and 5Kwh battery without panels, rather invest towards PV.

didn't you mention something about pool heating in that bundle? That may be the big price inflator, because that is certainly more than i paid.

 

[Bonywasawarrioraway]

I've got an existing Kwiksol 200 geyser (installed late 2018) and got a R25k quote to convert it to solar + 1 extra 1 x 2.5 SqM solar plate.... excessive?

convert not replace? yes thats absurd.

 

[Mier]

didn't you mention something about pool heating in that bundle? That may be the big price inflator, because that is certainly more than i paid.

I do have pool heating already. The quote only references this in relation to where on the roof the flat panel will be installed. "on roof next to pool heating system"

 

[charlieharper]

convert not replace? yes thats absurd.

Yes convert.

 

[Bonywasawarrioraway]

1 x 2.5 sqm collector panel is too small
I had 2, 2.5 sqm panels, these were just enough. Superb in summer, hopeless in (Cape Town) winter
When these failed due to corrosion, I got a 20 tube evacuated tube collector. Twice as efficient and more working days than non-working days
In winter, 2 hours of moderate sun heats the water to 60 deg

i agree with your size issues completely. You say panels failed due to corrosion? how long have you had them?
i'm in durban, brilliant in summer (water is practically boiling) unless we have a week of rain - which of course occurs here. in winter it still works providing no cold fronts with cold wind, then it uses electricity a lot and you need to make the "on " period longer. In cape town you might as well have it on permanently in winter. Brrrrrr praise the lord i no longer live there.... except for the government that is.

 

[Bonywasawarrioraway]

I do have pool heating already. The quote only references this in relation to where on the roof the flat panel will be installed. "on roof next to pool heating system"

oh ok. Then yes, that price is excessive. If you are in natal, try "solar primeg" or "solar beam" I have used both and both are reasonable. *caution* they hate each other. I don't know if they have a presence in the rest of the country.

 

[isie]

I hear what you are saying. I should have been more clear. the theory is this: in a pressure geyser as you use hot water, it is replaced in the geyser by cold water. In an electric geyser this immediately kicks in the element to return the whole volume to the preset temperature.
In a solar geyser the re-heat only occurs during the set time (on your fancy timer - this is the only time the element can engage.) or during the day when the sun shines again. Put simply it re-heats slower.

So, its is not about the volume of water as much as it is about the temperature of that water.

The amount one shower cools the water in the geyser by is determined by the ratio between how much water was used and the capacity of the geyser. So for the average shower the temp of the water in a small geyser will be reduced more than that in a large geyser. Ergo for this type of geyser bigger is better.

While they definitely save you money in the long run, make no mistake they are expensive. Buy one that is too small in order to save a few grand and you will suffer serious buyer's remorse and perhaps even be tempted to hold the view that they do not work and are a waste of time and money.

Most controllers are perfect for most people. Its just me with my disastrous working hours and therefore variable ablution times where they fall flat, and even then, only in winter. Ignore the controller comments, just me venting. The big issue you need to understand if you are not to be disappointed is the volume one.

Solar geysers are heated less frequently than electric so if you want to have enough hot water, you need a bigger one.

i hope that clears it up.

Ya i should have added controller def wont work for your schedule - you need like one That sync to your calendar
makes sense - technically it is about volume then but not volume required but volume of hot water left in the geyser vs volume of cold water coming in - so the temperature loss is not as much as it would be in a smaller geyser

 

[Mier]

oh ok. Then yes, that price is excessive. If you are in natal, try "solar primeg" or "solar beam" I have used both and both are reasonable. *caution* they hate each other. I don't know if they have a presence in the rest of the country.

Thanks. I'm in Somerset West though.

I settled on replacing the standard electric geyser for now and will probably retrofit later after proper research/quotes etc. It just feels too rushed to make such a big, unplanned investment decision in such short time.
However, the old geyser was 150L, which I'm replacing with 200L now. We're a family of four and even with the kids bathing at night and my wife and I in the mornings, the 150L has always been just too tight.

 

[Bonywasawarrioraway]

Thanks. I'm in Somerset West though.

I settled on replacing the standard electric geyser for now and will probably retrofit later after proper research/quotes etc. It just feels too rushed to make such a big, unplanned investment decision in such short time.
However, the old geyser was 150L, which I'm replacing with 200L now. We're a family of four and even with the kids bathing at night and my wife and I in the mornings, the 150L has always been just too tight.

I lived in gordon's bay for a spell. played golf in somerset west. loved it.

two things spring to mind.

one. although they don't have to be most of these solar installations have the geyser on the roof above the panels. This maximises the efficiency of water circulation through the panels via the old "warm water rises" thing. normal pressure geysers are usually in the ceiling. conversion later results in the geyser being below the panel with some loss of efficiency but better protection against corrosion. unless that is you move it when you convert, however the ones used on top of the roof have shielding that the regular ones do not so moving it is perhaps not viable. anyway you have done it now so don't worry about that.

two. size will really matter in your case. *picture scene*

150l electric . currently kids shower at night (using all available water as kids do). electric element heats water thru the night. you and the missus shower in the morning (together?) electric element heats water thru the day. kids sh..... rinse repeat you pay through the nose to eksdom.

enter solar. (200 l) god heats your water during the day. Kids shower at night (using... u get the picture) god is asleep just like u during the night (ignore the electric for now) so no heating occurs. you and the missus get no nookie in shower in the morning cos water is f-cking freezing . god heats the water for your kids during the day. they give eksdom the finger but u are unhappy.

but solar has electric backup. if you program it to turn on between kids shower and your morning "knippie" then all is well except that this means that only half the water you use is solar heated and you still heat the other half electrically. The installation is expensive and you only get 50% off your bill . eksdom pisses themselves and jacks up the price to compensate.

enter the 300l solar geyser. Kids shower at night using (on pain of death) reasonable amount of water. no heating occurs thru the night but there is still enough for shower in the morning. god heats it all during the day and you pay zilch. rinse repeat.

OR whole family can shower at night, you and missus first and kids after because kids use...... But you have to learn to shave at night because water will not be hot in the morning and because kids are still awake there will be no fun in the shower. god heats it all during the day and u pay zilch. edit : you might still be unhappy tho.

ceteris paribus of course meaning weather permitting, but at least most of the time eksdom is out of the picture.